


In Rut

by KandiSheek



Series: Kinktober 2019 [5]
Category: Marvel Cinematic Universe, The Avengers (Marvel Movies), The Avengers (Marvel) - All Media Types
Genre: (barely), A/B/O, Accidental Knotting, Alpha/Alpha, Alpha/Beta/Omega Dynamics, Both of them, Clueless Virgins, Dry Humping, Frottage, Hand Jobs, Kinktober, Kinktober 2019, Knotting Hands, Loss of Virginity, M/M, Plot What Plot/Porn Without Plot, Pre-Serum Steve Rogers, Rutting, Underage Sex
Language: English
Status: Completed
Published: 2019-10-05
Updated: 2019-10-05
Packaged: 2020-12-01 21:37:21
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,260
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20906540
Author URL: https://archiveofourown.org/users/KandiSheek/pseuds/KandiSheek
Summary: In a world where sexual urges only kick in when you present at eighteen, Bucky is a bit of an early bloomer. And as everyone knows he rarely does anything without dragging his best friend Steve along.





	In Rut

**Author's Note:**

> A couple things about this universe:  
\- Everyone presents as an alpha, beta or omega somewhere around their 18th-20th birthday. Before that hormone production is too low for any kind of sexual urges so people don't really explore their bodies on their own before their first rut/heat.  
\- This fic is set in the 30s, so sex ed is not really the done thing. Both Steve and Bucky have absolutely no clue what they're doing.  
\- The underage tag is there because they're both 16ish. If that's an issue for you, don't read this.
> 
> Now that that's out of the way, please enjoy!
> 
> Kinktober Prompt 05: Knotting

The pounding on their door made both Sarah and Steve jump where they were sitting at the kitchen table. Steve startled so badly he spilled the soup on his spoon all over the table, apologizing as he hurried over to the cabinet to fetch a towel while his mother went to get the door.

“Who is it?” she called out suspiciously and Steve joined her as quickly as he could, hands already in fists just in case the person knocking tried anything.

“It's us!” came a harried voice that Steve vaguely recognized but his mother clearly did because she opened the door without hesitation.

She quickly stepped aside as the woman pushed past her and when she pulled her hood back Steve saw that it was Winnifred Barnes, bundled up in a thick coat that was suspiciously lumpy because –

“Bucky?” Steve asked, noticing the brown hair sticking out of the coat but the other boy didn't react, just shuffled further into the warmth with a quiet groan.

“I'm so sorry.” Winnifred panted as though she had run all the way here, her eyes pleading as she looked at Sarah. “It's – too soon, by god the boy's barely sixteen, we weren't prepared and none of us are alphas –“

Sarah's eyes widened with understanding and she immediately shuffled Winnie along to the back of the house, unlocking the door to the room that Steve had only ever seen shut tight.

“In here,” she said and Winnie stepped inside with a grateful if harried smile, opening her coat to let Bucky settle down on the wooden floor.

Bucky whined, refusing to let go, and she shushed him gently, running a hand through his sweaty hair. “I know, I'm so sorry. I wish I could have explained before –“ Her voice broke on the word but she soldiered on. “It's not fair but you have to – I'm sorry, I can't be in here with you right now.”

With that she turned around and left, ignoring the whine of distress her son made as Sarah locked the door behind her. Winnie immediately started crying and Sarah took her in her arms, making soft shushing sounds as Steve just looked on in horror.

“What's wrong with Bucky?” he asked and Winnie shuddered before she cleared her throat and gave him a wobbly smile.

“Nothing bad, sweetheart. It's just –“

A wail from inside the room cut her off and her chin wobbled before she clasped a hand over it, choking on a sob. Sarah put an arm around her shoulder in comfort, giving Steve a serious look.

“Steve. You remember what I told you about alphas, betas and omegas?” Steve nodded. “Well, Winnie just found out that James is an alpha. When you're old enough you'll go through something similar.”

“But why lock him away?” Steve asked and Sarah's smile turned a bit dull at the edges.

“Well.” She cleared her throat. “Alphas are... when they go into their first rut it can be a little... overwhelming. James will need to stay in that room so he doesn't get hurt.”

Steve's eyes widened. “He could get hurt? But then someone should be there!”

Sarah averted her eyes with a wince. “It's, um. Not safe for one of us to be in there right now, baby.”

Steve hated when she called him that but his worry for Bucky far overshadowed that. “Why? I'm his friend, I should –“

“He could hurt you,” Sarah cut him off firmly. “I know he's your friend, Steve, but James isn't himself right now. He's safer on his own.”

Another blood-curdling moan from inside the door made them all jump and Steve heard a repetitive sound that reminded him of a dog scratching at the door. Winnie whimpered and Sarah sighed, pulling her towards the kitchen.

“Come on. I'll make us some tea.”

It was an uncomfortable evening. Now and then they would all hear Bucky shouting and pleading through the door which would make Winnie start crying until Sarah managed to calm her down just for the cycle to begin all over again. Steve sat in his father's armchair with a book, reading the same three sentences over and over again and wincing at every noise that came from that room, wishing he could be anywhere else.

Eventually his mother sent him to bed and Steve had never been more eager to go to his room and get away, practically sprinting up the stairs. His mother followed him at a more sedate pace to say goodnight and close the blinds. Just as she went to leave the room Steve spoke up very quietly so Bucky's mother wouldn't hear.

“Mom? What's happening to Bucky?”

She sighed, running a hand over her face as she turned back to sit on his bed.

“He's presenting," she said. "When you're old enough and your reproductive system is fully developed you have your first cycle. If you go into heat people know that you're an omega or a beta. If you go into rut you're an alpha. That's what James is going through.”

“Does he really need to be locked up?” Steve asked and Sarah gave him a tired smile.

“That room was your father's, you know? He was an alpha.” She got a sad look on her face when she said it and Steve grabbed her hand with both of his. The loss still stung for both of them. “Alphas are different from betas and omegas. The first few times when they're in rut they can't control the urge to mate. It's the hormones, they can make them... aggressive.”

Steve frowned. “Bucky's not like that.”

“I know he's not,” Sarah sighed, stroking Steve's hand with her thumb. “Your father wasn't either. But he told me that when he was young, before we bonded, he had... a hard time controlling himself during his rut. That's why he had this room.” Sarah gave Steve a crooked smile. “The Barnes family are all betas and omegas. They never had the need for a containment room. That's why she brought James here.”

Steve sat up to hug his knees to his chest, feeling small and helpless. “Is it that bad? The... urges?”

Sarah tilted her head in thought. “It's... well, I can't speak for alphas but a heat is unlike anything else. You'll see when you're older.”

“Maybe you'll need to lock me up too,” he said, wrinkling his nose when she winced. “Sorry.”

“It's okay,” Sarah sighed, running a hand through Steve's hair. “I know it's unfair but that's how it has to be. Alphas aren't... They just can't control themselves the way betas and omegas can. It's biology.”

Steve thought that sounded pretty unfair too but he also knew how much Bucky's mother loved her son. She would never do this if she didn't have to. “Okay,” he said after a moment of thought, nodding to himself. “I guess when the time comes you can lock me up too.”

Sarah chuckled, ruffling his hair as she stood up. “We don't know what you're going to be yet, Steven. Don't you worry about that.”

They said their goodnights as she blew out the candle by his bedside before leaving the room. Steve must've fallen asleep at some point because the moon was high and bright in the sky when he woke up next, rubbing his eyes grumpily. His throat was parched and his bladder too full to go back to sleep so Steve quietly got out of bed, padding across the floor and grabbing a jacket before he went to the outhouse to relieve himself.

He was freezing by the time he came back in, silently closing the door and securing it with the metal chain. He'd just reached the sink to fetch himself a glass of water when he suddenly heard a moan from the closed room down the hall. Steve froze.

“Bucky?”

The sound came again, louder this time, accompanied by the same scratching from before. Steve cautiously crept down the hallway when a scent suddenly hit his nose, loud and sharp and so unlike his own or his mother's. He sniffed the air, his feet leading him towards it on their own until he was standing right in front of the closed door.

Steve put his hand up against it. The smell reminded him of long summer nights spent under a blanket, huddling together, and the sound of giggling in his ears –

A stab of pain suddenly lanced through him, almost like a stomach cramp, and Steve gasped, holding his stomach with both hands. Oh god, he could smell it even stronger now, tangy and almost sweet on his tongue.

He groaned, doubling over, and the noises from behind the door got even louder, more distressed. It pulled at something deep inside Steve that made him whine high in his throat, reaching for the lock –

But strong hands grabbed him, pulled him away, and Steve _wailed_, struggling to get free, get back to that smell –

“Steve!” His mother's voice was sharp and Steve's head snapped up, looking at her with wide eyes, his chest heaving with heavy breaths like he was having an asthma attack.

“Mom...”

“What's going on?” Winnie asked as she stormed into the hallway, all color draining from her face when she saw Steve. “Oh my god!”

“This shouldn't be happening,” Sarah said and she sounded just as distressed. “Unless...”

“No,” Winnie gasped, bringing a hand to her mouth, and Steve didn't understand, he just wanted to go back, get to – to _Bucky_ –

Steve took a gasping breath, clutching at his mother's arm when his knees suddenly gave out under him. Sarah caught him with a yelp, holding him tight as he whimpered.

“What's happening to me?” he asked, his voice trembling with fear. Sarah held him tight, her face grim when she looked at him.

“Steve... you – you smell like –” Her eyes widened. “Oh.”

“What?” He yelped, groaning when another lance of pain hit his stomach. “But I – I –“

“You're too young to present,” Sarah said bluntly. “Something else must've triggered it.”

Steve's eyes immediately snapped to the door down the hallway, a soft whine trapped in his throat. Winnie sucked in a sharp breath.

“Sarah?”

“We need to put him inside,” Sarah said decisively, looking at her friend with a cross between desperation and determination. “It's gonna kick in soon and he – it won't be safe out here. For him. Or us. Our neighbors are all omegas, I can't –”

Winnie's eyes were wide but she nodded, walking down the hallway in long strides as Sarah followed, struggling to hold on to Steve.

“Shh, hey, it's okay,” Sarah murmured but it didn't have the same calming effect it usually did. Steve felt like he was burning up from the inside and when he got another whiff of that tantalizing scent the pain in his stomach started feeling strange, almost like he was hungry but not quite –

“Quick!” Sarah barked and Winnie opened the door. The smell got overwhelming all at once and Steve gasped, lurching forward to follow it –

And something clamped onto him even before the door was fully shut, pulling him inside. There was only little moonlight coming in through the window but Steve didn't need it, burrowing his nose where the smell was the strongest and –

“Oh!” Bucky gasped, his hips suddenly jerking forward and knocking them off balance. They tumbled to the floor under their combined weight, rolling around and snarling at each other until Steve got a good grip and twisted his legs just right and –

He yelped, his grip tightening on Bucky's shoulder when Bucky's hip brushed against his crotch and he thrust forward on instinct, eyes rolling back into his head at the feeling, so _good_ –

“Fuck!” Bucky snarled and it was like a dam had broken, both of them clutching at each other and mindlessly rutting forward, rubbing against something – _anything_ –

Steve's stomach felt weird, almost like he had to pee, and it scared him how good it was, like nothing he'd ever felt before –

_Heat,_ his mind supplied, but then he buried his face in Bucky's neck and the_ smell_ on him, god –

Steve yelped when he felt pressure low in his stomach, his cock stiff and sensitive like never before and – “Bucky!”

Bucky groaned, still rutting into Steve with reckless abandon as Steve's back arched and he thought he would explode, how could his body contain this much _feeling_ –

Something in him snapped and his crotch got suddenly and shockingly wet as he squirmed against Bucky's thigh. Steve was absolutely mortified, thinking he'd peed his pants, but it didn't feel like he had, it felt – oh _god,_ it felt –

And then it was over. Steve felt like he was floating, his brain buzzing with static, but Bucky's whimper brought him back. He tried to pull away, whining when Bucky kept thrusting against him and it hurt now, it was way too much –

“Stop!” he gasped and Bucky loosened his grip even though he was still vibrating with tension, his eyes wild when Steve saw them glinting in the moonlight.

“I can't!” Bucky groaned, still rutting against Steve's hip – thankfully not his crotch anymore – and Steve could feel something hard against him –

He reached down without thinking, grabbing Bucky through his pants and Bucky jolted like he'd been struck by lightning, moaning from somewhere deep in his chest. With jerky movements Bucky pushed his pants down, kicking them off without any grace, and Steve's eyes widened when he saw that it was Bucky's _penis,_ standing hard and thick in a thatch of curls. Was this what had happened to him? His dick _had_ felt pretty stiff –

Before he could react Bucky had grabbed Steve's hand and wrapped it around his cock, moaning like he was dying as he gripped Steve's hand with his own, squeezing it tighter to create a small space for him to thrust into. Steve could only watch, equally fascinated and – something else as he looked at Bucky's face contorted in what seemed like pain. He jolted when he felt something squishy against his palm on the next thrust and –

“Holy shit!” he breathed, staring at where Bucky's cock was swelling. “Oh my god, are you okay?”

“I don't know,” Bucky whined through clenched teeth, his shoulders hunched. “I need – need –“

Steve reached out with his other hand to touch the lump at the base of Bucky's cock and Bucky _shouted,_ eyes wide open as he threw his head back. Steve twitched when Bucky's cock suddenly throbbed in his hand and – oh. Well, at least he knew that he didn't pee his pants now.

Bucky kept making tiny whimpery noises through it all and Steve moved to pull his hand away, remembering how sensitive he'd been after – but Bucky clamped onto his wrist with an iron grip, staring at Steve with something like panic.

“No!”

Steve froze, fingers squeezing down on reflex, and Bucky's eyes almost bugged out of his head before they rolled back as his cock shot out more of that – whatever that was. It was a lot, kept dribbling down over their joined hands as Bucky's hips jolted under them.

For a moment they were silent, reeling in the aftermath of what just happened. Then Steve cleared his throat.

“So, uh. Can I have my hands back now?”

Bucky's grip tightened and he shook his head frantically. “Not – not yet. Please.”

Steve sighed in annoyance. “You're done, aren't you?”

“I don't... know?” Bucky's voice wobbled and Steve sighed, lying down next to him with his hands still around Bucky's cock.

“How did... I mean, did it... feel good? For you too?”

“Yeah,” Bucky sighed, turning his head to sniff at Steve's neck. His whole body twitched and he moaned, wetting his cock with another load. He was bright red when Steve turned to raise an eyebrow at him. “You, ah. You smell. Different.”

“You too,” Steve hummed, nuzzling into Bucky's hair. “I like it.”

“Me too,” Bucky said quietly and after that there wasn't really anything to say so they just lay there together, breathing deep and slow as Bucky's body relaxed bit by bit.

Steve was a bit surprised when he felt the knot in his hand start to deflate but bit his tongue so Bucky wouldn't feel awkward. After that it was only a couple of minutes before Bucky tentatively removed their hands from his cock, sighing in relief as he finally slumped against Steve.

“So...” Bucky cleared his throat. “That was sex, right? We... had sex?”

“I guess so,” Steve said, wrinkling his forehead. “I don't know why... I mean, I smelled you and I just... had to get in here.”

“Weird,” Bucky mumbled, already half asleep and now that the excitement was over Steve could feel his own eyes drooping. Bucky wrapped his arms around him, cuddling him like a teddy bear, and it should've been uncomfortable but Steve dropped off to sleep right away, safe and warm in his hold.

The next morning they both sat at the kitchen table, fidgeting uncomfortably under their mothers' combined gaze.

“So,” Sarah said and they both preemptively winced. “We have a lot to talk about.”

Bucky grimaced. “Is there any chance we could maybe skip this talk, Mrs Rogers?”

“James Buchanan!” His mother scolded him and Bucky sunk even deeper into his chair. “This is important and you will listen to what Sarah has to say.”

“Yes, mom,” Bucky mumbled and Steve had to hide a smile at that.

“So,” Sarah started again, folding her hand on the table. “As I'm sure you're aware what happened yesterday wasn't... how these things usually go.”

They both nodded sheepishly.

“James, you presented as an alpha,” Sarah said before she took a deep breath and looked at Steve. “And Steve, you're an alpha too.” Steve frowned in confusion but before he could ask Sarah continued, tapping the side of her nose. “I could smell the hormones on you.You didn't present last night, not really. What you felt was your body responding to Bucky's rut. I assume after... you were done doing whatever you did you went right back to normal?”

Steve blushed furiously at the memory of Bucky and him rutting together. “Yeah.”

Sarah nodded, a resigned look on her face. “It's something very rare. You and Bucky, you're bond mates.”

The boys looked at each other in confusion.

“But... I thought...” Steve said slowly. “Only alphas and omegas mate?”

Sarah grimaced. “That's – well. There have been cases...”

“It's not normal,” Winnie stated bluntly, crossing her arms. “But it happens. Usually it's because... well, because the alphas or omegas share a third mate.” She gave them both a brittle smile. “I guess you're such good friends that you'll take care of an omega together.”

Both Steve and Bucky stared at their mothers with wide eyes before they looked at each other.

“That's... cool, I guess,” Bucky finally said, a grin spreading on his face. Steve giggled, punching Bucky in the shoulder.

“Guess you're stuck with me, jerk.”

“Til the end of the line. I told you, punk,” Bucky said and there was no way to miss the fondness in his eyes.

Sarah and Winnie looked at each other, the same expression of reluctant pride and fear on their faces. This would make life hard on their boys, constantly fighting the stereotypes and prejudice of others, but... Judging by the looks in their eyes and the way Bucky had grabbed Steve's hand almost possessively –

Yeah. Their boys would be alright.

**Author's Note:**

> There's a sequel to this now called "Boiling Up". Just in case you're interested in who their third partner is ;)  
Thanks for reading!


End file.
